In a construction machine such as a power shovel, a liquid-sealed mount is used to improve a ride quality of an operator who rides on a cab (operator's cabin). The liquid-sealed mount is positioned between the cab and a vehicle body frame, supports the cab, and absorbs and damps vibration so that the vibration is not transmitted from a vehicle body frame side to a cab side.
For example, Patent Documents 1 and 2 each discloses a liquid-sealed mount where a movable damping plate is positioned in a housing in which highly viscous liquid is sealed, the movable damping plate is connected to an upper stud, and a lower part of the movable damping plate is supported by a spring member. For example, the stud is connected to the cab, and the housing is connected to the vehicle body frame.
In these liquid-sealed mounts, the vibration in up and down direction of the cab applied to the vehicle body frame is absorbed mainly by elastic deformation of the spring, and the vibration absorbed by the spring is damped by a flow resistance of the liquid when the movable damping plate connected to the stud is moved in the highly viscous liquid.
Patent Document 3 discloses a liquid-sealed mount including an attachment member having a connecting bolt protruded upward; a support cylinder member; an elastic support connecting one end of the support cylinder member to the attachment member, the other end of the support member being closed by an elastic diaphragm member, a liquid chamber in which a liquid is filled being separated into a pressure receiving chamber and an equilibrium chamber by a divider and both the chambers being in communication with each other through an orifice; a bevel-shaped member protruded from the attachment member to a receiving chamber side; and a cup-shaped member having a connection bolt protruded downward and fixed to a rear surface side of the elastic diaphragm member, which is connected by a caulking part so as to close a lower end opening side of the support cylinder member. For example, the attachment member is connected to an engine side, and the cup-shaped member is connected to a vehicle body side.
In the liquid-sealed mount, a vibration in a vertical direction of an engine to a vehicle body is absorbed mainly by elastic deformation of the elastic support, and the vibration absorbed by the elastic support is damped by a flow resistance of the liquid moving between the pressure receiving chamber and the equilibrium chamber through the orifice.
Patent Document 4 discloses a vibration control apparatus including an inner cylinder metal member having an implant bolt protruded upward; an outer cylinder metal member; an elastic body connecting one end of the outer cylinder metal member to the inner cylinder metal member, the other end of the outer cylinder metal member being closed by a diaphragm, a liquid chamber in which highly viscous liquid is filled being separated into two chambers by a damping plate attached to a lower end of the inner cylinder metal member, which are in communication with each other through a gap formed between an outer peripheral end of the damping plate and an inner periphery of a concave part of the elastic body; a cap member disposed at a rear surface side of the diaphragm, protruded downward and fixed to a lower end of the outer cylinder metal member; and a gas chamber configured of the diaphragm and the cap member, a gas being sealed in the gas chamber. For example, the inner cylinder metal member is connected to a cabin, and the outer cylinder metal member is connected to a vehicle body.
In the liquid-sealed mount, a vibration in a vertical direction of the cabin to the vehicle body is absorbed mainly by elastic deformation of the elastic support, and the vibration absorbed by the elastic support is damped by a flow resistance of the highly viscous liquid through which the damping plate connected to the inner cylinder metal member is moved.
Patent Document 1: Japanese Patent Application Laid-open No. H08-254241
Patent Document 2: Japanese Patent Application Laid-open No. 2003-322198
Patent Document 3: Japanese Patent Application Laid-open No. H07-54912
Patent Document 4: Japanese Patent Application Laid-open No. H09-280299